Engine starting mechanism



June 5, 1945. R. M. NARDONE ENGINE STARTING MECHANISM Filed July 23,1942 4 Sheets-Sheet 1 mm m June 1945. R. M. NARDONE ENGINE STARTINGMECHANISM Filed July 23,.1942 4 sheets sheet 2 INVENTOR.

June 1945- R. M. NARDONE ENGINE STARTING MECHANISM Filed July 23, 1942 4Sheets-Sheet 5 I N VENTOR. 30mm 17. flares 0M! BY e w R. M. NARDONEENGINE STARTING MECHANISM June 5, 1945.

Filed July 25, 1942 4 Sheets-Sheet 4 I N VENTOR. 30mm 1 1. Nardone mi wvt 4..-

HTTORNEY Patented June 5, 1945 ENGINE STARTING MECHANISM Romeo M.Nardone, Westwood, N. J., assignor to Bendix Aviation Corporation, SouthBend, Ind., a corporation of Delaware Application July 23, 1942, SerialNo. 452,071

2 Claims.

This invention relates to engine starting mechanism of the inertia type.

Operation of mechanism of this character usually involves accelerationof the inertia element, or elements, prior to movement of theengine-engaging element of the starter to engineengaging position. Thisaccelerating process may be manual, or it may involve use of powerderived from an electric motor. My Patent No. 2,068,462 shows an inertiastarter having an inertia element in the form of a flywheel which may beaccelerated manually or by use of an electric motor; the connectionsbetween the motor and flywheel involving a uni-directional clutch whichoverruns when the manual accelerating means is employed-the motor thusremaining at rest, wherefore its commutator and brushes do not act as adrag on the flywheel during the acceleratin process.

While this elimination of brush drag is desir able under theseconditions of manual acceleration, there are occasions when the additionof the mass of the motor armature, to that of the flywheel, wouldprovide a desirable increase in the total inertia effect, which increasewouldv be even more substantial if the brush drag were to be removed. I

In my Patent No. 2,261,402 there is disclosed a brush lifting mechanismoperative to remove the brushes from contact with the motor commutatorwhenever it is desired to employ the manual accelerating means foractuating the flywheel, with the motor armature rotating therewith, toadd to the inertia efiect.

The present invention is based upon the concept of removing brush drag,whenever desired, by a different method, namely, by slackening thetension of the springs of the brush assembly, so that the brushes ridefreely on the commutator surface, rather than being mechanically liftedout of contact with the commutator, as in my prior Patent 2,261,402,above referred to; the ultimate result being the same, to wit, a freerotation of the armature, unrestricted by any appreciable brushpressure.

As is well known, brush springs are commonly employed to ensuresufllcient firmness of contact, as between the brush ends, on the onehand, and the commutator surface on the other. These springs arepreadjusted to the desired degree of the motor assembly, and by meansthat are operable from an external point, just prior to commencement offlywheel acceleration, when manual flywheel acceleration is to beresorted to; said spring varying means being otherwise locked in theposition corresponding to normal spring pressure on all brushes.

These and other objects of the invention will become apparent frominspection of the following specification when read with reference tothe accompanying drawings wherein is illustrated the preferredembodiment of the invention. It is to be expressly understood, however,that the drawings are for the purpose of illustration only, and are notdesigned as a definition of the limits of the invention, reference beinghad to the appended claims for this purpose.

In the drawings:

Fig. l is a longitudinal sectional View of a starting mechanism havingmy invention incorporated therein;

Figs. 2 and 3 are end views of the unit shown in Fig. 1;

Fig. 4 is a sectional view along line 4-4 of Fig. 1;

Fig. 5 is a sectional view of the jaw-engaging solenoid; and

Figs. 6, 7 and 8 are end and side views of the brush pressurecontrolling means.

In the drawings there is shown a representation, mainly diagrammatic, ofone type of engine starting mechanism to which the present invention isapplicable. As shown therein the flywheel 5 is disposed in alignmentwith the electric motor 8 constituting one of the alternativeacceleratin means referred to above; hub 6 of the flywheel being keyedto armature shaft 1. interposed between the engine-engaging clutchmember 9 and the flywheel 5 are the usual gear train and capacitycontrolling pre-set clutch, the former being shown as having at one enda high speed pinion ll rotatable with flywheel 5, and at the low speedend a set of planet pinions I2 to rotate the barrel I3 housing thepre-set clutch I! in the usual manner, (as illustrated in detail inLansing Patent No. 1,833,948) whereby rotation is imparted to the engineengaging clutch element 9. Movement of the clutch member 9 intoengagement with corresponding clutch member [0 of the engine is underthe control of axially movable rod l6 passing centrally and slidablythrough clutch barrel l3 and adapted to actuate clutch member 9 throughyieldable means l5, as in the aforesaid Lansing patent. The rod I6 isnormally restrained in the clutch-retracting position shown, by suitablemeans such as coiled torsion spring I? (Fig. 2) corresponding to thecoiled torsion spring N6 of the aforesaid Lansing patent, and is movableinto the clutch meshing position by manual means attachable to the endportion id or bell-crank i9 (Fig. 2) or by energization of a solenoid 23whose plunger 2| (see Figs. 2 and connects with rod l5 by way of theintervening bell-crank i9 and the rockshaft 24 (Fig. 2) about which thespring H is coiled; the said rocksnaft having the usual lever 26attached at its inner end for pivotal connection with rod |6. Adjustablescrew 31 (Figs. 2 and 5) transmits, to section 38 of bell-crank I 8, thethrust of plunger 21, when solenoidju is energized. Spring i1 isthe-opposing (and plunger returning) force.

In case of motor failure (or if the battery charge is weak) the startermay be operated by accelerating the flywheel by hand through thehand-cranking shaft 33 connecting with hub 21 of the barrel I3, by wayof gears 34, 35 (Fig. 1). Hub 2! also serves as a support for sun gear39.

The brush pressure controlling mechanism is shown in Figs. 4, 6, 7 and 8as including a ring 4| having support upon a circular inner surface ofthe end section 49 of the motor housing; said ring 4| being shiftableabout said supporting member 49 to a limited extent as determined by thelength of arcuate slot 58 (Fig. 3) on the end surface of housing member45, which slot receives a pin 46 (Figs. 1, '7 and 8) secured at itsinner end to the section 41 of the ring 4|, and at its outer end havinga head 5| (Fig. 1) for retention of a coiled spring 54 and a manuallyoperable knob 53 whose base 55 is slidable on pin 46 and normally restsin a circular depression 45 of housing member 49, to lock the ring 4|against rotation until such time as the knob 53 is manually pulled out,preparatory to shifting of the ring 4| for relaxation of brush pressure.The relaxation of brush pressure follows upon shifting of the ring 4| byreason of the action of levers 43 whose end pins 44 are located in slotsformed in plates spaced evenly about the ring 4| at locationscorresponding to the locations of the commutator engaging brushes 16.For each brush 16 there is a spring Tl wound spirally about, andanchored to, a post, 80; the said posts 80 being keyed to, and hencerotatable by the levers 43 as the latter are shifted by rotation of thering 4|; each lever and post assembly being journaled in a bushing 41(Fig. '7) of non-conducting material, and all of said bushings 81 beingembedded in the supporting yoke 40 which carries the brush-holding boxes19. The yoke 40 is in turn secured to the housing member 8 by suitablemeans 86 (Figs. 1 and 8). 7

It will be noted that each lever 43 has a range of movement over an arcof about sixty degrees, which means that each spirally wound spring 11will be wound or unwound to a corresponding degree each time the leversare swung, through manipulation of knob 53. This alternate winding andunwinding produces alternate application and release of engagingpressure on the brushes l6, and in each case the condition isself-retained, due to the action of spring 54 (Fig. 1) in holding thebase 55 of knob 53 in one or the other of the two depressions 45, saidtwo depressions being located at opposite ends of arcuate slot 58 (Fig,3).

What is claimed is:

1. In a motor having a commutator and a plurality of commutator-engagingbrushes, a plurality of spirally coiled springs having their inner endsanchored at their respective axes, one for applying pressure to eachbrush, means for simultaneously uncoiling all of said springs to a.predetermined degree, while the brushes remain in contact with thecommutator, said uncoiling means comprising a corresponding plurality oflevers, each adapted to swing about the axis of coiling of itscorresponding spring, and a single means for simultaneously swinging allof said levers, said single means including a locking mechanism forretaining the levers in the positions to which they have been swung.

2. In a motor having a commutator and a plurality of commutator-engagingbrushes, a plurality of spirally coiled springs having their inner endsanchored at their respective axes, one for applying pressure to eachbrush, means for simultaneously uncoiling all of said springs to apredetermined degree, while the brushes remain in contact with thecommutator, said uncoiling means comprising a corresponding plurality oflevers, each adapted to swing about the axis of coiling of itscorresponding spring, and a single means for simultaneously swinging allof said levers.

ROMEO M. NARDONE.

